This research is primarily designed to define a safe and reliable method for the antenatal diagnosis of the major hemoglobinopathies including sickle cell anemia and Cooley's Anemia. The methods involve either aspiration of the placenta after localizaton by ultrasound or amnioscopic detection of chorionic plate vessels and aspiration of fetal cells from them by direct visualization. Preliminary technical studies will be performed in a pregnant rhesus monkey model. Methods for concentration of fetal cells from a mixture of maternal cells will also be defined. Finally we will investigate certain aspects of the gamma beta switch mechanism to determine whether this switch is at least partially influenced by translational as well as transcriptional control.